Conventional pneumatic vehicle tires consist of an outer casing which is given the desired load-bearing capacity and elasticity by air pumped into the casing (tubeless) or into an inner tube fitted within the casing (tubed). Unfortunately, such pneumatic tires are subject to explosive decompression when punctured. Therefore, there has long been needed for a tire and an economical way for producing a tire that would eliminate losing the entire volume of compressed air from within a pneumatic tire when it is punctured.
Methods and apparatuses have been developed to produce a “flatproofed” tire. Liners of various types have been provided in the tire or between an inner tube and the tire casing serving to mitigate the effects of the tire casing being punctured. A more prevalent method for overcoming the problem is to convert pneumatic tires to solid or semi-solid composite tires. Such tires have gained a wide acceptance for certain mining, industrial, and construction uses where the added weight, and different dynamic performance characteristics could be tolerated for permanent protection from flat tires. Until recently, such solid deflation-proof tires have depended on a foamed elastomer filling. Since the foamed filling in such tires is easily flexed, the tires have disadvantages. For example, excessive heat can build-up within the tire and cause the filling to breakdown during service. Filling breakdown reduces the amount of support provided by the foamed elastomeric material potentially causing damage to usually expensive equipment. Therefore, a change from merely using elastomeric material for a filling was required.
Prior to the current invention, a technique for making a flatproofed tire included taking a used flatproofed tire, cutting it into a number of large chunks, placing these chunks into casing of a tire and adding sufficient unused flatproofed material to fill any remaining voids. This method however also has numerous drawbacks. The first drawback is that this procedure can only be used to produce tubeless tires. The second drawback is that this procedure is both labor and time intensive. For example, the used tires have to be manually cut into chunks, those chunks arranged in a casing so as to maximize the shape occupied by the chunks and then an unknown about of new flatproofed material added to fill any voids. In addition to the drawbacks mentioned above, this method produces a tire with inferior properties as the poor bonding of the chunks and new flatproofed material yields a tire that is subject to premature breakdown.
Another method of producing a flatproofed tire currently uses all new flatproofed material. This material is pumped directly into the casing to produce a flatproofed tire. However, this method also has several drawbacks. First a tire produced by this method runs at a relatively high temperature thus leading to breakdown at an increased rate. Second, the input of only pure unused flatproofed material takes a longer time to set-up or cure because the input is at a lower temperature than available when the unused flatproofed material is bonded with large chunks of recycled flatproofed tires. Therefore a process and apparatus that can provide a flatproofed tubeless or tubed tire in a manner that yields a flatproofed tire with superior properties, while reducing the time and labor required in production is needed.